Pore Structures and Adsorption Properties of Fluorinated Activated Carbon Fiber

抄録

N₂ adsorption and XPS elucidated the surface states of fluorinated activated carbon fiber (F-ACF) and fluorinated carbon black. The XPS examination showed that the C-F bonds are not ionic, but covalent. The N₂ adsorption isotherms of F-ACF was of Type I and the adsorption was predominant at a low P/P₀ region, although the total adsorption amount of F-ACF decreased. The fluorination reduced the pore width of ACF by 0.21nm. Only external nanographitic layers of three stacking sheets were fluorinated, considering from the crystallite size from X-ray diffraction and the chemical analysis. The increase of the pore-wall thickness by the fluorination of the nanographitic sheets agreed with the decrease of the pore width by fluorination. Adsorption isotherms of H₂0, CH₃OH, and C₂H₅OH were measured. The fluorinated ACF showed a perfect hydrophobicity. Also adsorption isotherms of CH₃OH and C₂H₅OH on F-ACF had an S-shaped nature at the low P/P₀ region, while their adsorption isotherms ofACF were of Type I.